RAET1E and neoplasm: Due to upregulated self-antigen expressions in the transformed tumor cells, Vγ9Vδ2-T cells discriminate these malignant cells by directly binding to these self-antigens (49), such as HSP 60, ULBP-4, hMSH2, and F1-ATPase, which can enhance the activation and cytotoxicity of Vγ9Vδ2-T cells.